Protein A affinity chromatography is frequently the method of choice to purify antibodies and other Fc-containing proteins (see “Purification Tools for Monoclonal Antibodies” by P. Gagnon, 1996, Validated Biosystems, Inc., Tucson, Ariz., Chapt. 9, Protein A Affinity Chromatography). A preparation containing antibodies is loaded onto a Protein A affinity chromatography resin, washed, and eluted, usually with either a low or high pH buffer. Purification as high as 95% in one step can be achieved.
The price of Protein A affinity chromatography resins is many times the cost of non-affinity supports. In a commercial manufacturing process, this raw material cost can significantly add to the cost of goods. Protein A affinity chromatography resins can be recycled in order to reduce the cost of raw materials. Typically, Protein A affinity chromatography resins are recycled by treatment with strong chaotropic solutions (urea and guanidine hydrochloride), or strongly acidic solutions (such as acetic acid), or a combination thereof. However, these recycling methods often lead to a decrease in column performance Additional methods of regenerating chromatography materials, such as protein A resin are needed therefore.